Monthly Projected Revenue

I have a similar question

I would recommend creating a child table for invoices and either scheduling all of them out or using a pipeline to create them initially.  That gives you the reporting benefit you requested but also lets you do future things like track if they are paid, when paid, etc.

My recommendations:

Create a child invoice table
Create a checkbox on the parent table (probably an order or customer table) that will be used to trigger the pipeline.  You will never use this checkbox
Create a formula URL button (or rich text button if you want more aesthetic control) and call it Schedule out Invoicing.  Use that button to "check" the checkbox you creatd
Create a pipeline to run when that checkbox is checked.  It should loop through the months and create the invoices as required.